Chapter 8.3, Problem 130E

Preliminary data analyses indicate that you can reasonably apply the t-interval procedure (Procedure 8.2 on page 355) in Exercises 8.129–8.134.

8.130 Digital Viewing Times. According to eMarketer, the average time spent per day with digital media in 2010 was 3 hours and 14 minutes. For last year, a random sample of 20 American adults spent the following number of hours per day with digital media.

Find and interpret, a 90% confidence interval for last year’s mean time spent per day with digital media by American adults. (Note: $\bar{x}$ = 5.16 hr and s = 2.30 hr.)